Regulatory mechanism on enhancing proteinsynthesis in skeletal muscles of cold exposed fresh water fish (Channa punctata)

Channa punctata varieties of fish are energetic and survive in critical environment although the molecular mechanism is not known. They were exposed to cold (4–8 _C) for 30 min, 1 h, 2 h and 4 h and the total protein contents in the liver were not significantly changed up to 4 h of cold exposure while a significantly increased protein level in the skeletal muscle was noted and maximal at 2 h. Groups of fish were exposed to Na2HAsO4 to examine its role on cold-induced protein synthesis in the skeletal muscle and the increased protein in the skeletal muscle was reduced significantly. The results appear to indicate that cold acclimation induces a metabolic change involving cellular protein content tissue specifically and arsenic might be involved in impairment of the cold-induced effect. To clarify the molecular mechanism, groups of fish exposed to cold for 1 h and 2 h had significantly increased RNA in the skeletal muscle compared to control fish, however, a higher level was found after 2 h of treatment and the enhanced RNA induced by cold was almost completely prevented by Na2HAsO4. Our findings will give a new insight into the survival process of this species while toxic arsenic prevents this cellular bioprocess.